Differential Diagnosis for Left Shoulder Injury
The patient presents with a 2-week history of left shoulder pain and discomfort after a twisting injury. The following differential diagnoses are considered:
- Single most likely diagnosis
- Subacromial Impingement or Rotator Cuff Strain: The patient's symptoms of sharp pain, popping sensation, and continued discomfort with extension are consistent with a rotator cuff injury or subacromial impingement. The improvement with Tylenol and ibuprofen also suggests a musculoskeletal etiology.
- Other Likely diagnoses
- Adhesive Capsulitis (Frozen Shoulder): Although less likely given the acute onset, adhesive capsulitis can occur after a traumatic injury. The patient's limited range of motion and discomfort with extension could be consistent with this diagnosis.
- Labral Tear: A labral tear can occur with a twisting injury and may cause sharp pain and a popping sensation. The patient's symptoms and mechanism of injury make this a possible diagnosis.
- Bursitis: Inflammation of the subacromial or subdeltoid bursa can cause shoulder pain and discomfort, especially with extension.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Proximal Humerus Fracture: Although the patient did not report a significant trauma, a proximal humerus fracture can occur with a twisting injury. This diagnosis would require prompt attention to avoid complications.
- Axillary Nerve Injury: An injury to the axillary nerve can cause shoulder pain, weakness, and numbness. This diagnosis would require prompt evaluation and treatment to avoid long-term sequelae.
- Thoracic Outlet Syndrome: Compression of the neurovascular bundle can cause shoulder pain, numbness, and weakness. This diagnosis would require prompt evaluation and treatment to avoid long-term complications.
- Rare diagnoses
- Osteonecrosis of the Humeral Head: Although rare, osteonecrosis can occur after a traumatic injury. The patient's symptoms and mechanism of injury make this a possible, albeit rare, diagnosis.
- Infection (Septic Arthritis or Osteomyelitis): Infection is a rare but possible cause of shoulder pain and discomfort. The patient's symptoms and lack of systemic symptoms (e.g., fever, chills) make this diagnosis less likely.